This invention relates to disc brakes and more particularly to caliper or "spot" type disc brakes.
A typical caliper or "spot" type disc brake generally comprises a rotatable brake disc and a nonrotatable caliper having legs that straddle the brake disc. A friction lining carrier having an arcuate friction lining or facing secured thereto is usually nonrotatably mounted adjacent to each leg of the caliper and is capable of being pressed into contact with the rotatable brake disc. The surface of the friction linings are of a much smaller area than the area of the associated friction surface of the rotatable brake disc. The friction linings are usually designed to be replaced after they have become worn.
Some caliper type brake designs require complete removal of the caliper assembly from its associated wheel for replacement of the friction linings. More recent brake designs have been aimed at providing means to remove and replace worn friction linings quickly and conveniently without disassembling the brake housing or other parts of the brake assembly. One of the latter type of brake designs is disclosed in U.S. Pat. No. 3,357,524, assigned to the assignee of the present invention.
The brake assembly disclosed in U.S. Pat. No. 3,357,524 has end or "thrust" plates connected to a caliper housing to restrain movement of the friction lining carriers in all directions except the direction in which the friction lining is pressed toward the rotatable brake disc. The thrust plates transmit the braking torque from the rotatable disc to the nonrotatable housing. As a further feature of the brake disclosed in U.S. Pat. No. 3,357,524, each lining carrier is fully supported at each end by a thrust plate.
To remove a friction lining carrier from the type of caliper disc brake disclosed in U.S. Pat. No. 3,357,524, it is merely necessary to remove a thrust plate from one end of the housing. The carrier can then be removed by sliding it from between the housing and the rotatable brake disc through the opening created by the removed thrust plate in a direction parallel to the friction surface of the rotatable brake disc. This is easily accomplished without removing or disassembling the housing itself or the brake actuation mechanism.
Although designs such as U.S. Pat. No. 3,357,524 have greatly improved the serviceability of caliper type disc brakes, further improvements are still possible. For example, the procedure of removing a thrust plate may be simplified by eliminating the removal of numerous screws or other fasteners. Furthermore, a removable thrust plate can be misplaced, and is often difficult to arcuately reposition when being replaced.